Field of the Invention
The present invention relates to a golf club head. Specifically, the present invention relates to a golf club head in which different types of materials are combined.
Description of the Related Art
A coefficient of restitution and a volume of a head are regulated by the rule. In light of a swing balance, a weight of a head is restricted. The regulation and the restriction complicate the design of a head having enhanced performance.
In order to overcome the regulation and the restriction, a golf club head in which different types of materials are combined has been known. A degree of freedom of the design of a head can be enhanced by a combination of different types of materials. For example, a combination of materials having a specific gravity different from each other can enhance a degree of freedom of the design for a position of the center of gravity of the head.
Japanese Patent No. 3885023 (US2003/0125127) discloses a head in which a hole is provided on a crown part of a head body, and the hole is closed with a cover member made of a material different from a material of the head body. The cover member has a specific gravity smaller than a specific gravity of the head body. Specifically, the specific gravity of the head is equal to or greater than 1.3 times the specific gravity of the cover member. In the head, a flange is formed at a peripheral edge of the crown part, a peripheral edge portion of the cover member is divided into two layers, and the flange is sandwiched by the two divided layers.